1,721,407 research outputs found
Birational geometry of moduli of curves with an S3-cover
Full text linkWe consider the space Rg,[email protected]@3344bf5e of curves with a connected S3-cover, proving that for any odd genus g≥13 this moduli is of general type. Furthermore we develop a set of tools that are essential in approaching the case of G-covers for any finite group G
Singularities of moduli of curves with a universal root
Full text linkIn a series of recent papers, Chiodo, Farkas and Ludwig carry out a deep
analysis of the singular locus of the moduli space of stable (twisted) curves
with an -torsion line bundle. They show that for and
pluricanonical forms extend over any desingularization. This
allows to compute the Kodaira dimension without desingularizing, as done by
Farkas and Ludwig for , and by Chiodo, Eisenbud, Farkas and Schreyer
for . Here we treat roots of line bundles on the universal curve
systematically: we consider the moduli space of curves with a line bundle
such that . New loci of canonical
and non-canonical singularities appear for any and
, we provide a set of combinatorial tools allowing us to completely
describe the singular locus in terms of dual graph. We characterize the locus
of non-canonical singularities, and for small values of we give an
explicit description.Comment: 30 pages, to appear in Documenta Mathematic
Moduli spaces of abstract and embedded Kummer varieties
Full text linkIn this paper, we investigate the construction of two moduli stacks of Kummer varieties. The first one is the stack of abstract Kummer varieties and the second one is the stack of embedded Kummer varieties. We will prove that is a Deligne-Mumford stack and its coarse moduli space is isomorphic to , the coarse moduli space of principally polarized abelian varieties of dimension . On the other hand we give a modular family of embedded Kummer varieties embedded in P^{2^g-1}\timesP^{2^g-1}, meaning that every geometric fiber of this family is an embedded Kummer variety and every isomorphic class of such varieties appears at least once as the class of a fiber.
As a consequence, we construct the coarse moduli space of embedded Kummer surfaces and prove that it is obtained from by contracting the locus swept by a particular linear equivalence class of curves. We conjecture that this is a general fact: \boldsymbo{K}^{em}_g could be obtained from via a contraction for all g>1
At home and abroad: An empirical analysis of innovation and diffusion in energy technologies
No full textIssue for Climate Change: Technical Change, Coalitions, Uncertainty. FEEM Reports
No full textFeem Newslette
Some properties of planar polynomial systems of even degree
No full textWe prove that a planar polynomial vector field of even degree always has an unbounded solutio
Multiparametric Semi-quantitative Scoring System for the histological evaluation of marine fish larval and juvenile quality
Full text linkGilthead seabream (GSB - Sparus aurata) and European seabass (ESB - Dicentrarchus labrax) are two of the most farmed fish species in EU. However, production of sea bream/bass in the EU has remained stagnant for the last decade and the Mediterranean EU aquaculture faces significant sustainability challenges. In consideration of this, and as it is largely recognized that the success of marine aquaculture strictly depends on the production of good quality larvae/juveniles, in this paper the authors put forward an original standardized tool for the histological assessment of GSB and ESB larva/juveniles. This tool promptly allows to highlight problems in marine fish larval batches because of managerial practices, suggesting to fish farmers which direction take to resolve them. A Multiparametric Semi-quantitative Scoring System (scoring range 1–5) has been originally developed for larval/juvenile histological evaluation and it includes 18 descriptors related to 6 organ districts. The values of each descriptor can be summarized in two indexes: the CHI (Cumulative Histological Index), giving general information about the quality of a fish batch in that precise moment and the OCV (Organ condition value) showing the general condition of each organ and by the individual descriptors. The paper purposes are to describe the MSSS, the criteria established for the score attribution and to supply some indications for the use of the tool
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